Hit squad

Real-time strategy is tough to do properly on tablets and smartphones. There are usually just too many components to juggle on a simple touchscreen interface.

Just about the best way around this that we've seen in recent years is to reduce the scale of the game and lessen the number of units you're responsible for.

This is why the strategy bits of Call of Duty: Strike Team were actually pretty good fun. Of course, that game also had terrible shooting sections and limited tactical options.

Line of Defense Tactics aims to create a pure squad-based RTS game within a slick (and pre-existing) sci-fi universe. And it mostly succeeds.

Strong quartet

You guide a compact four-person team of space marines on a series of sorties into hostile space ships, stations, and planets. Each has its own unique load-out and abilities, which develop and expand as you accrue experience.

Your team can be loosely broken down into a medic, a sniper, a heavy-weapons guy, and a grunt, but each has a range of additional abilities that mark them out as unique. For example, the sniper can spot enemies from farther away, so makes for a good scout, while the grunt's secondary weapon is an energy lance for close combat.

The interface is pretty simple. Touch on a free area of the screen to direct your whole team, or touch and drag specific characters to move, attack, or take up defensive positions. You can also direct them into cover, as displayed via a yellow 'shield' icon near doors and boxes, which significantly reduces the damage they take from frontal attacks.

Take an enemy unawares (there's a stealthy sneak option too) or stun it with a stun grenade and you can even quickly incapacitate it - provided you can get close enough without being detected.

Control under pressure

The control system works well in general, though it can get fiddly at times. It can be difficult to pick out individual team members when they're clustered into corridors, or to direct the whole team small distances from where they're standing.

The method of using certain key skills, such as the medic's heal ability, also seems a little long-winded.

IAPs explained

You get the first three levels of the campaign for free. You can then unlock the full campaign for £2.99.

It's also possible to purchase additional CEP points for purchasing new equipment, which will cost you 69p for 200 (that will buy you a new grenade or turret), £2.49 for 1000, and topping out at £34.99 for 16000.

You can also unlock a second free-form skirmish map for £1.49.

In general, though, the developer has managed to squeeze a great deal of tactical flexibility into a reasonably intuitive interface. You can lob grenades, change weapons, deploy gun turrets, hunker down, and more, all with a few taps.

We were slightly less convinced by the space-faring missions, which see you directing a sluggish cruiser and fending off attacks. The ability to switch between various missile types, deploy shields, and focus your gun turrets is fun, but it just feels like one of those dull on-rails sections in a shooter - a kind of breather from tactical considerations that isn't strictly necessary.

There aren't many of them, but given that there are only 16 campaign missions in total, we would have preferred more of the normal levels instead.

All in all, Line of Defense Tactics is one of the most convincing squad-based RTS efforts we've encountered. It still needs to clean up and better explain its UI, and a greater level of focus is required, but those tantalised by some what Call of Duty: Strike Team promised should take a look.